<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>p8_绝对定位</title>
  <style>
    .fu {
      background-color: #ff0;
      /* 子绝父相 */
      position: relative;
    }
    .fu>div {
      width: 100px;
      height: 100px;
    }
    .z1 {
      background-color: #f00;
    }
    .z2 {
      background-color: #0f0;
      /*绝对定位：会脱离文档流、释放布局空间
      移动参照物：离自己最近的，有非静态定位属性的上层元素 */
      position: absolute;
      top: 50px;
      left: 50px;
    }
    .z3 {
      background-color: #00f;
      /*position: absolute;*/
      position: relative;
    }
  </style>
</head>
<body>
<!-- .fu>.z*3 -->
<div class="fu">
  <div class="z1"></div>
  <div class="z2"></div>
  <div class="z3"></div>
</div>
</body>
</html>